The present invention relates generally to metering devices for granular and flaky materials, and more particularly to a metering device wherein a metering cavity is filled with a predetermined quantity or dose of material by a movable hopper member which in its upper position causes material to move by gravity into the metering cavity and which in its lower position positions material in the hopper cavity below the rim of the metering cavity.
In many metering and measuring applications, and particularly in measuring material used with water pipes known as narghiles or hookahs, it is required for proper use that a particular quantity or measure of flaky or granular material, such as tobacco, be metered into a pipe bowl at frequent intervals for burning. This has long been done manually by pouring the material into a measuring cup or device from a separate container. Such procedures are tedious, inaccurate, inconvenient, and require a separate, movable container for decanting material which is not readily pourable because of inter-granular friction and the consistency of the materials.
Typical prior art devices depend upon discharge of flaked or granular material from the base of a hopper into a measuring cavity by the opening of a valve, or by reciprocation of a slider having a measuring cavity into and out of registration with a hopper base, as shown in U.S. Pat. No. 4,044,781 to Heggestuen. Such devices are characterized by certain shortcomings, including unreliability because of internal inter-granular friction of the flaked or granular substances, such as shredded tobacco, which do not readily flow by gravity, and which may not fill the measuring cavity upon the opening of the hopper base thereto.
It is therefore an object of the present invention to provide metering means for filling upwardly facing metering cavities with flaky or granular material, wherein flow of material from a free surface into measuring cavity overcomes difficulties inherent in the inter-granular friction and consistency of such materials.
It is an object of the invention to provide a metering device for use with water pipes and the like, wherein the tobacco or herb to be smoked is supplied from a material cavity of a movable hopper which in its upper limit position causes material to flow by gravity into a bowl metering cavity, and when moved into its lower position has the material therein below the rim of the metering cavity.